Free Money Day, an annual event on September 15 to promote sharing economies. Photo by @Donmacca on Flickr (CC-BY-2.0)

Citizens from 24 countries handed strangers free money on September 15, 2012, in order to raise awareness about the benefits of economies based on sharing. The annual Free Money Day is an initiative of PostGrowth, an international network committed to creating global prosperity without economic growth.